MODULE VII
TIME MOTION STUDY
I.
OBJECTIVE
To give the students practical experience in time studies and to provide an insight
to the problems faced in time studies.
Praktikan dapat mampu menggunakan / membaca stopwatch, mencatat waktu
siklus, mem-“breakdown” pekerjaan menjadi elemen-elemen kerja dan
menentukan rating pekerjaan.
II.
DISCUSSION
Every production process has to have a systematic procedure for developing
production standards (time standards). Three techniques have been used to
determine time standards: estimates, historical records, and work measurement
procedures.
Estimates are time standards established based on judgment rather than facts.
Historical records also rely on past data, which may have been obtained either by
estimates or work measurement techniques.
Work measurement techniques- stop watch time study, standard data, time
formulas, or work sampling studies- represent a better way to establish fair
production standards. All of the work measurement techniques are based upon
facts.
Work measurement techniques consider each detail of work and its relation to the
normal time required for performing the entire cycle. Accurately established time
standards make it possible to increase efficiency.
Time standards can be utilized for:
1. Production planning purposes.
2. Comparison of alternative methods.
3. Effective plant layout.
4. Determining capacities.
5. Purchasing new equipment.
6. Balancing work force with the available work.
7. Production control.
8. Installation of incentives.
9. Standard cost and budgetary control.
Time study is a technique for establishing an allowed time standard to perform a
given task. This technique is based upon measurement of the work content of the
prescribed method, with due allowance for fatigue, and for personal and
unavoidable delays.
Time studies should be used to measure the amount of work that can be produced
by a qualified employee when working at a normal pace and effectively utilizing
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his time where work is not limited by process limitations. It is also important that
the method be standardized for the process.
For ease of measurement, operation can be divided into group of motions, known
as elements. Analyst should watch the operation cycles if he wants to divide the
operation into its individual elements. Element can be defined as a component of
job or task that are logical divisions with easily identifiable starting and end points,
and are repeated on a regular basis. Element breakdown is a separation of a work
cycle into elemental motions. The work cycle in this case is the completion of the
activities (elements) that is required to perform the jobs under study. So, with this
separation of the elements motion, it will make us easier to do the analysis of the
motions.
1.
Calculate the Normal Time
=
2.
Calculate the Standard Time
=
3.
(
)
Calculate the Output Standard
=
OT
R
NT
ST
OS
III.
IV.
= Operating Time (
= Rating performance of operator
= normal time
= standard time
= output standard
EQUIPMENT
1. Stopwatch
2. Stecker
3. Screwdriver
4. Observations sheet
PROCEDURE
1. Familiarize yourself with the stopwatch.
2. Using the stecker parts provided, perform the assembly task. After an operator
finishes two jobs, change the operator to reduce the effects of learning. Each
one of the group members will be performing the task and measuring the time.
3. Determine the elements within the task, and write them on your time study
form.
4. Collect 10 cycles of pilot data.
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V.
ANALYSIS
Part 1:
1. Performance rating is a part of the time study process. What rating would you
provide to supplement the time data you collected? (How much did the
operator produce during the time you made your observations, relative to
what you would expect from a “normal” operator? )
2. Determine mean time and standard deviation for each element.
3. Determine the number of cycles to observe for a time study, based on these
pilot data.
a. Which element will you base your calculations on?
b. How many cycles should you study to be within ± 5% of the “true” time for
that element with a confidence of 95%?
4.Based just on the data you have already collected, with 95% confidence, within
what percent of the average of the “true” mean is your estimate? (in other
words, what is k?)
Part 2:
Assume that you conducted your actual time study, and the average cycle time
turned out to be the same as for the pilot study you conducted.
1. In order to calculate the standard time for the task, allowance(s) are typically
added for PFD. What allowances do you think should be included for this
particular task? Briefly explain your response.
2. Calculate the standard time for the task.
3. What would the hourly production rate be for one operator?
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Figure 7. Time Study Sheet
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